#! /usr/bin/env python
import os
import stat


def collect(dir, dir_st, results):
    total = 1
    try:
        names = os.listdir(dir)
    except OSError, e:
        results.append((True, '?', dir))
    else:
        subcollects = []
        for name in names:
            if dir == '.':
                path = name
            else:
                path = os.path.join(dir, name)
            try:
                st = os.lstat(path)
            except OSError:
                pass
            else:
                if stat.S_ISREG(st.st_mode):
                    total += st.st_blocks
                elif stat.S_ISDIR(st.st_mode):
                    if st.st_dev == dir_st.st_dev:   # one file system only
                        subcollects.append((path, st))
        for path, st in subcollects:
            total += collect(path, st, results)
        results.append((False, total, dir))
    return total

def display(results):
    results.sort()
    for _, info, dir in results:
        if isinstance(info, (int, long)):
            info = str(info / (1024*1024/512))
            if info == '0':
                continue
        print '%6s  %s' % (info, dir)

if __name__ == '__main__':
    import sys
    results = []
    for fn in sys.argv[1:] or ['.']:
        collect(fn, os.stat(fn), results)
    display(results)